Transmission-dynamometer for direct observation.



K. SUYEHIRO.

TRANSMISSION DYNAMOMETBB FOR DIRECT OBSERVATION.

APPLICATION rum) PEBJ, 1913.

13,105,382, Patented July 28,1914.

CEo

Specification of Letters Eatent.

Patented July as, 1914,

Application me February 7, 191a. Serial in. 748,858.

To all whom it may concern:

Be it known that I, KYOJI SUYEHIRO, a subject of the Emperor of Japan,residing at N 10 'Nishikata Machi, Hongo-Ku, Tokyo, Empire of Japan,have invented certain new and useful Improvements inTransmission-Dynamometers for Direct Observa tion; and I do herebydeclarethe following" to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

This invention is to make transmission dynamometers directl observableby forming the image of sea e of indicator which indicates an amount oftwist in or near the center of-a shaft-by means of mirrors or lenseswhich are fitted in'proper positions. As the image is formed in or nearthe center it remains alwa in the center during the revolution of the saft, the only motion be ing self-revolution. Therefore the image-ispractically at rest for the range of observation, and can be observed'ust like a scale or indicator on a fixed sha t. Its object is to' makethe scale or indicator indicating the amount of twist of transmissiondynamometer directly observable by a simple method and thereby tosimplify the con-, lstruction of transmission dynamometers.

It is a well known law of physics, that if an object be placed before amirror a virtual image of that object will seem to appear as far behindthe mirror as the object is distant w ,therefrom, and also that a lensmay be so disposed relatively to an object, that a similar image will becaused to appear at a predetermined distance from the lens, dependoutupon the varying focal distance. I The broad object of the presentinvention, therefore, is to mount an optical element (such as a mirror,prism, or lens) relatively to an indicator or scale, mounted on androtating with a shaft, so as to cause a virtual image of the indicatoror scale to seemingly appear substantially at the axis of rotation ofsaid shaft, whereby the image is practically at rest during the timeofrobservation.

With these objects in view the invention consists in the arrangement andcombination of parts hereinafter referred to, the particular features ofnovelty being pointed out more succintly in the appendedclaims.

To more fully understand the invention reference is had to theaccompanying drawings illustrating a practical embodiment of the same,in which drawings like charaoters designate the same or equivalent partsin the several views, and in which- Figure 1* is an edge view inelevation, showing a spring transmission dynamometer fitted vith thepresent invention. Fig. 1 is: a view in side elevation of the same,onehalf of one of the disks being broken away, showing a pair of thesprings in elevation, and also showing the relative positions of thescale and mirror. Fig. 2 is a plan yiew showing a modified constructionfor ind cating the torsional stress between two positions, on a shaft.Fig. 2 is a view in elevation taken at right angles to Fi 2. Fig. 2 is across sectional view throng the shaft, at a position substantiallybetween the pair of scales and showing the sition of one of the scalesrelatively to the shaft. Fig. 3 is a' plan view, Fig. 3 is anelevational view and Fig, 3 is an-end view, illus tratingdiagraimnatically .a modified arrangement, in which the scale isilluminated by the reflection from the mirror of a suita 19 light suchas. an electric-lamp. Fig. 4 is a plan view, Fig. 4, an, elevationalview, and Fig. 4 ,anend view illustrating a modified arrangement inwhich a mirror or prism is arranged obliquely to the shaft, and alsoshowin the scale directly illuminated by a suitabe light, and Fig. 5A isa lan view, Fi fi 'an elevational view, and ig. 5 an en view, showing afurther modified form in which the scale disposed between the shaft anda lens, the same being so p0 sitioned relatively to each other that avir tual image of thescale is caused to base pro ected as to; a parentlybe-seen ata position substantially at;the axis of rotation of saidshaft.In these views the scale is also shown as beinm directly illuminatedbyalamp. v H

As shown in Fig. I the amount of twist between two circular disks (A)and (B) of instance, be indicated y a pair of scales (c and ((1,). Butthey are not observable while the shaft is running. For. the purpose ofmakingiethe scales observable, the images of the sea ter of the shaft bymeans of a mirror (6,) fitted just or nearly midway between the scales(in) and (a and. the-center oithe shaft (0 of)t and parallel to thecenter line of the she a spring transmission (1- namometer'cam-for s areformed in or near the oen In the torsionmeter which is shown in Fig. 2the twist between two points (P) and (Q) is indicated, for instance, bya pair of scales (a and ((1 one of the scales (a being mounted on aprojecting arm (A which is fixed at a point (P) b means of a tube (R),and the other scale (2 being mounted on the other projecting arm (Bwhich is directlyfixed to the shaft at a point (Q). To make the scalesobservable, a mirror (6 is fitted just in the same manner as before.

' In Fig. 3 the arrangement is shown diagrammatically. In the figure,(a) is a scale or an indicator and (b) a mirror. As described in theforegoing paragraphs, the mirror (b) is fitted just or nearly midwaybetween the' scale (a) and the center of the shaft (0) in order that theimage of the scale or indicator (6) be formed in-or near the center ofthe shaft. Though the scale or indicator (a) 1 itself changes itsposition while revolving, its image (2') remains in the center of theshaft, the only motion-being self-revolution. If the size of the mirror(6) is not large the observable range during whichthe scale is reflectedinto the eyes of an observer by the mirror" is very small; As shown in(C) of Fig. 3, when the shaft turns by a sufliciently large angle (6)the image takes a position (i 0) where the reflected rays of thescalecan no more enter into the eyes.

I Thus, as the image (i)'seems as if it were at rest during a smallrange and this is re peated at each revolution successively, the

image (i) seems likea fixed scale or indicator and can easily beobserved. If the scale (a)- is well illuminated by an" electric-lamp (e)theimage'appears verydistinctly. In the-above arrangement it isnecessary, that the distance of the scale-or indicator (0:). from thesurface of the shaft 'is longer that the radius ofthe shaft. If not, theima e can not be formed in the centerof the she Referring to Fig. a, inthe case where this construction is not: desirable a scale or indicator03 indicating twist is placed normal to the direction of the shaft (00') and a mirror (a prism may be'used in lieu of the mirror) is fittedobliquely to the shaft. As

. shown in I the figure the obliquity "(angle '0 In." it

In actual cases;'however,it need not nece's I sarily be a plane mirror,the surface of the mirror, may be curved. Then in an arrangement asshown in Fig. 3, the mirror is not fitted in the middle of the distancebetween the scale or indicator (0) and the center of the shaft (0 0) butat a proper position between them, according to the curvature of thesurface of the mirror to form the image in or near the center of theshaft. If the arrangement be as shown in Fig. 4 the position of themirror and its obliquity (angle 0 0 b) are so adjusted according to thecurvature of the surface of the mirror, that the image (11) is formed inor near the center of the shaft. Again, if, according to theconstruction of a dynamometer, a mirror according to the position of thescale or in dicator (0,) as to form the image near the center of theshaft.

Claims: t

' 1. In a transmission dynamometer for indicating the torsional stresson ashaft, the combination of indicating means mounted on and rotatingwith the shaft, and an optical element mounted on the shaft andcooperating with said. indicating means to cause a virtual. image ofsaid indicating means to appear substantially at the axis of rotation ofsaid shaft. Y Y

2; In a transmission dynamometer for in dicating the torsional stress ona'shaft, the combination 'of indicating means carried by said shaft, andan optical element carried by (11) in or said shaft and disposed betweensaid shaft N0 appear substantially at the axis of rotation R5 of saidshaft.

1 3. ln-a transmission dynamometer for indicating the torsionalstress'ona shaft, the

combination of an indicating element carried by the shaft, an opticalelement carried by the shaft, and coiiperating with said indicatingelement tocause 'a'virtualimage of said indicating element to appearsubstantially at the axis of rotation of said'shaft, and means forilluminating one of saidelements to=cause the image to appear moreclearly. lntestimon whereof, afix. my signature, inpresence 0 twowitnesses. 1 V KYOJI SUYEH-IRQ. Q

-- Witneseeez? T F. Nnersisr, T

GENJI KUTIBARA.

